* vaxbsd-nat.c (vaxbsd_supply_gregset, vaxbsd_collect_gregset):

Use `gdb_byte *' for regs.
* vax-tdep.c (vax_supply_gregset): Use `gdb_byte *' for regs;
(vax_store_arguments, vax_push_dummy_call, vax_return_value): Use
gdb_byte for buf.
(vax_breakpoint_from_pc): Change return type to `const gdb_byte
*'.  Use gdb_byte for break_insn.
(vax_skip_prologue): Use gdb_byte for op.